Full Idea
What makes something a priori is not the means by which it came to be known, but the means by which it can be shown to be true or false.
Gist of Idea
'A priori' does not concern how you learn a proposition, but how you show whether it is true or false
Source
J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §4.01)
Book Reference
Baggini,J and Fosl,P.S.: 'The Philosopher's Toolkit' [Blackwells 2003], p.134
A Reaction
Helpful. Kripke in particular has labelled the notion as an epistemological one, but that does imply a method of acquiring it. Clearly I can learn an a priori truth by reading it the newspaper.